powerpc/eeh: Refactor the output message

We needn't the the whole backtrace other than one-line message in
the error reporting interrupt handler. For errors triggered by
access PCI config space or MMIO, we replace "WARN(1, ...)" with
pr_err() and dump_stack(). The patch also adds more output messages
to indicate what EEH core is doing. Besides, some printk() are
replaced with pr_warning().

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 41 insertions, 16 deletions

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 416fb432d7e2..3a8f82fd9005 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -329,7 +329,9 @@ static int eeh_phb_check_failure(struct eeh_pe *pe)
         eeh_serialize_unlock(flags);
         eeh_send_failure_event(phb_pe);
 
-        WARN(1, "EEH: PHB failure detected\n");
+        pr_err("EEH: PHB#%x failure detected\n",
+                phb_pe->phb->global_number);
+        dump_stack();
 
         return 1;
 out:
@@ -458,7 +460,10 @@ int eeh_dev_check_failure(struct eeh_dev *edev)
          * a stack trace will help the device-driver authors figure
          * out what happened.  So print that out.
          */
-        WARN(1, "EEH: failure detected\n");
+        pr_err("EEH: Frozen PE#%x detected on PHB#%x\n",
+                pe->addr, pe->phb->global_number);
+        dump_stack();
+
         return 1;
 
 dn_unlock:
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 0974e1326842..2b1ce17cae50 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -425,6 +425,7 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
          * status ... if any child can't handle the reset, then the entire
          * slot is dlpar removed and added.
          */
+        pr_info("EEH: Notify device drivers to shutdown\n");
         eeh_pe_dev_traverse(pe, eeh_report_error, &result);
 
         /* Get the current PCI slot state. This can take a long time,
@@ -432,7 +433,7 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
          */
         rc = eeh_ops->wait_state(pe, MAX_WAIT_FOR_RECOVERY*1000);
         if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) {
-                printk(KERN_WARNING "EEH: Permanent failure\n");
+                pr_warning("EEH: Permanent failure\n");
                 goto hard_fail;
         }
 
@@ -440,6 +441,7 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
          * don't post the error log until after all dev drivers
          * have been informed.
          */
+        pr_info("EEH: Collect temporary log\n");
         eeh_slot_error_detail(pe, EEH_LOG_TEMP);
 
         /* If all device drivers were EEH-unaware, then shut
@@ -447,15 +449,18 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
          * go down willingly, without panicing the system.
          */
         if (result == PCI_ERS_RESULT_NONE) {
+                pr_info("EEH: Reset with hotplug activity\n");
                 rc = eeh_reset_device(pe, frozen_bus);
                 if (rc) {
-                        printk(KERN_WARNING "EEH: Unable to reset, rc=%d\n", rc);
+                        pr_warning("%s: Unable to reset, err=%d\n",
+                                   __func__, rc);
                         goto hard_fail;
                 }
         }
 
         /* If all devices reported they can proceed, then re-enable MMIO */
         if (result == PCI_ERS_RESULT_CAN_RECOVER) {
+                pr_info("EEH: Enable I/O for affected devices\n");
                 rc = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
 
                 if (rc < 0)
@@ -463,6 +468,7 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
                 if (rc) {
                         result = PCI_ERS_RESULT_NEED_RESET;
                 } else {
+                        pr_info("EEH: Notify device drivers to resume I/O\n");
                         result = PCI_ERS_RESULT_NONE;
                         eeh_pe_dev_traverse(pe, eeh_report_mmio_enabled, &result);
                 }
@@ -470,6 +476,7 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
 
         /* If all devices reported they can proceed, then re-enable DMA */
         if (result == PCI_ERS_RESULT_CAN_RECOVER) {
+                pr_info("EEH: Enabled DMA for affected devices\n");
                 rc = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
 
                 if (rc < 0)
@@ -482,17 +489,22 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
 
         /* If any device has a hard failure, then shut off everything. */
         if (result == PCI_ERS_RESULT_DISCONNECT) {
-                printk(KERN_WARNING "EEH: Device driver gave up\n");
+                pr_warning("EEH: Device driver gave up\n");
                 goto hard_fail;
         }
 
         /* If any device called out for a reset, then reset the slot */
         if (result == PCI_ERS_RESULT_NEED_RESET) {
+                pr_info("EEH: Reset without hotplug activity\n");
                 rc = eeh_reset_device(pe, NULL);
                 if (rc) {
-                        printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc);
+                        pr_warning("%s: Cannot reset, err=%d\n",
+                                   __func__, rc);
                         goto hard_fail;
                 }
+
+                pr_info("EEH: Notify device drivers "
+                        "the completion of reset\n");
                 result = PCI_ERS_RESULT_NONE;
                 eeh_pe_dev_traverse(pe, eeh_report_reset, &result);
         }
@@ -500,11 +512,12 @@ static void eeh_handle_normal_event(struct eeh_pe *pe)
         /* All devices should claim they have recovered by now. */
         if ((result != PCI_ERS_RESULT_RECOVERED) &&
             (result != PCI_ERS_RESULT_NONE)) {
-                printk(KERN_WARNING "EEH: Not recovered\n");
+                pr_warning("EEH: Not recovered\n");
                 goto hard_fail;
         }
 
         /* Tell all device drivers that they can resume operations */
+        pr_info("EEH: Notify device driver to resume\n");
         eeh_pe_dev_traverse(pe, eeh_report_resume, NULL);
 
         return;
diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
index 85025d7e6396..0cd1c4a71755 100644
--- a/arch/powerpc/platforms/powernv/eeh-ioda.c
+++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
@@ -853,11 +853,14 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
                                         phb->eeh_state |= PNV_EEH_STATE_REMOVED;
                                 }
 
-                                WARN(1, "EEH: dead IOC detected\n");
+                                pr_err("EEH: dead IOC detected\n");
                                 ret = 4;
                                 goto out;
-                        } else if (severity == OPAL_EEH_SEV_INF)
+                        } else if (severity == OPAL_EEH_SEV_INF) {
+                                pr_info("EEH: IOC informative error "
+                                        "detected\n");
                                 ioda_eeh_hub_diag(hose);
+                        }
 
                         break;
                 case OPAL_EEH_PHB_ERROR:
@@ -865,8 +868,8 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
                                 if (ioda_eeh_get_phb_pe(hose, pe))
                                         break;
 
-                                WARN(1, "EEH: dead PHB#%x detected\n",
-                                     hose->global_number);
+                                pr_err("EEH: dead PHB#%x detected\n",
+                                        hose->global_number);
                                 phb->eeh_state |= PNV_EEH_STATE_REMOVED;
                                 ret = 3;
                                 goto out;
@@ -874,20 +877,24 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
                                 if (ioda_eeh_get_phb_pe(hose, pe))
                                         break;
 
-                                WARN(1, "EEH: fenced PHB#%x detected\n",
-                                     hose->global_number);
+                                pr_err("EEH: fenced PHB#%x detected\n",
+                                        hose->global_number);
                                 ret = 2;
                                 goto out;
-                        } else if (severity == OPAL_EEH_SEV_INF)
+                        } else if (severity == OPAL_EEH_SEV_INF) {
+                                pr_info("EEH: PHB#%x informative error "
+                                        "detected\n",
+                                        hose->global_number);
                                 ioda_eeh_phb_diag(hose);
+                        }
 
                         break;
                 case OPAL_EEH_PE_ERROR:
                         if (ioda_eeh_get_pe(hose, frozen_pe_no, pe))
                                 break;
 
-                        WARN(1, "EEH: Frozen PE#%x on PHB#%x detected\n",
-                             (*pe)->addr, (*pe)->phb->global_number);
+                        pr_err("EEH: Frozen PE#%x on PHB#%x detected\n",
+                                (*pe)->addr, (*pe)->phb->global_number);
                         ret = 1;
                         goto out;
                 }